B - Operations – Transporting – 60 – K
Patent
B - Operations, Transporting
60
K
341/68
B60K 17/02 (2006.01) F16H 61/06 (2006.01) F16H 59/38 (2006.01) F16H 59/68 (2006.01) F16H 61/00 (2006.01)
Patent
CA 2023987
ADAPTIVE POWERED DOWNSHIFT CONTROL OF AN AUTOMATIC TRANSMISSION Abstract of the Disclosure In an automatic transmission, clutch-to-clutch powered downshifting is controlled by filling the on-coming clutch at a low pressure while ramping down the off-going clutch pressure until turbine speed is pulled up due to off-going clutch slippage, and then increasing the off-going pressure stepwise to compensate the change from static to dynamic coefficients of friction. Then the on-coming pressure is gradually ramped up and a closed-loop profile control period starts wherein the slip speed of the on-coming clutch is measured and controlled to a slip speed profile by controlling the off-going clutch pressure. When synchronization of the on-coming clutch is first detected, a closed-loop sync control period starts wherein the off-going pressure is controlled to minimize the slip and the on-coming pressure is ramped up at a steeper rate to begin clutch engagement during the sync control period. Adaptive control is accomplished for the initial on-coming pressure by an iterative process which decreases that pressure stepwise until flare occurs and then increases the pressure to stop the flare and repeating the changes in smaller steps to approach the flare condition. Initial off-going pressure is modified when early slip or late slip of the off-going pressure is detected. A modification of off-going pressure step value is effected when the final pressure in the closed-loop period is greater or smaller than the initial pressure. The modifications are targeted to fully correct the respective conditions.
Lentz Carl A.
Runde Jeffrey K.
General Motors Corporation
Gowling Lafleur Henderson Llp
LandOfFree
Adaptive powered downshift control of an automatic transmission does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Adaptive powered downshift control of an automatic transmission, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Adaptive powered downshift control of an automatic transmission will most certainly appreciate the feedback.
Profile ID: LFCA-PAI-O-2032637